<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>相机Camera相机配置</title>
  <script src="../three.js/build/three.js"></script>
  <style type="text/css">
     div#canvas-frame {
        border: none;
        cursor: pointer;
        width: 100%;
        height: 600px;
        background-color: #EEEEEE;
    }

</style>
<script>
    var renderer;
    function initThree() {
        width = document.getElementById('canvas-frame').clientWidth;
        height = document.getElementById('canvas-frame').clientHeight;
        renderer = new THREE.WebGLRenderer({
            antialias : true
        });
        renderer.setSize(width, height);
        document.getElementById('canvas-frame').appendChild(renderer.domElement);
        renderer.setClearColor(0xFFFFFF, 1.0);
    }

    var camera;
    function initCamera() {
        camera = new THREE.PerspectiveCamera(45, width / height, 1, 10000);
		//camera = new THREE.OrthographicCamera( window.innerWidth / - 2, window.innerWidth / 2, window.innerHeight / 2, window.innerHeight / - 2, 10, 1000 );
        camera.position.x = 0;
        camera.position.y = 0;
        camera.position.z = 600;
        camera.up.x = 0;
        camera.up.y = 1; //星际位置定好之后，还要设置相机是如何摆放的，这个表示相机的y方向向上
        camera.up.z = 0;
        camera.lookAt({
            x : 0,
            y : 0,
            z : 0
        });
    }

    var scene;
    function initScene() {
        scene = new THREE.Scene();
    }

    var light;
    function initLight() {
        light = new THREE.AmbientLight(0xFF0000);
        light.position.set(100, 100, 200);
        scene.add(light);

        light = new THREE.PointLight(0x00FF00);
        light.position.set(0, 0,300);
        scene.add(light);
    }

    var cube;
    function initObject() {
        var geometry = new THREE.CylinderGeometry( 70,100,200);
        var material = new THREE.MeshLambertMaterial( { color:0xFFFFFF} );
        var mesh = new THREE.Mesh( geometry,material);
        mesh.position = new THREE.Vector3(0,0,0);
        scene.add(mesh);
    }

    function threeStart() {
        initThree();
        initCamera();
        initScene();
        initLight();
        initObject();
        animation(); //这里不断去执行动画函数，

    }
    function animation()
    {
        changeFov();
        renderer.render(scene, camera);
        requestAnimationFrame(animation); //动画循环
    }

    function setCameraFov(fov)
    {
        camera.fov = fov;
        camera.updateProjectionMatrix();
    }

    function changeFov()
    {
        var txtFov = document.getElementById("txtFov").value;
        var val = parseFloat(txtFov);
        setCameraFov(val);
    }
        </script>
    </head>

    <body onload="threeStart();">
      <div id="canvas-frame"></div>
      <div>
         Fov:<input type="text" value="45" id="txtFov"/>(0到180的值)
     </div>
 </body>
 </html>
